Before we move on to the applications of Diode Laser, let us first look at its characteristics. The wavelength of this laser is a key characteristic. We will also see how it differs from other lasers. This article will give you a clear picture of the different types of Diode Lasers. You can also use this information to determine if the laser you consider is right for your needs.
Its description
The diode laser is a semiconductor light-emitting diode, and it works by exchanging energy between its electrons and holes. In this laser, the electricity moves free electrons from an n-type material to a p-type semiconductor. While some of these electrons interact with the valence electrons in the n-type material, others recombine with holes in the p-type semiconductor and emit light. The energy released is called spontaneous emission.
A diode laser is an excellent choice for hair removal, as it uses a single wavelength of light to heat up the melanin in the follicle. The heat from this light destroys the hair follicle root, thereby reducing the follicle’s ability to grow. In addition, many quality laser hair removal machines incorporate refrigeration contact cooling. This cooling system protects the skin’s surface during the treatment and allows for a more comfortable treatment. Since diode lasers deliver low fluence pulses, this type of laser is suitable for people with all skin types.
Its characteristics
The diode laser is a semiconductor, meaning that the crystal’s atoms share their electrons with four neighbors. The semiconductor has a band-gap structure, and the gain zone is an enclosed area. The optical cavity limits the amount of light that can be focused on a single facet, and the narrow waveguide reduces the total volume of the laser cavity. The ridge-cutting process increases the crystal’s pore size, which decreases the front facet’s power density.
The output optical power of a diode laser varies according to the current flowing through the laser diode. The output optical power is very low when the current is below the threshold current and increases dramatically once the current rises above the threshold value. Typical threshold currents lie in the range of 25 mm, and output powers range from 1 to 10 mW. Despite this, the diode’s characteristics are essential to understand when choosing a laser.
Its applications
A diode laser is a surgical tool with a wavelength ranging from eight to ten microns (nm). This makes it an excellent choice for procedures involving soft tissue. The wavelength of a diode is especially well-suited for mucosal surgery, as it has high absorption by hemoglobin and melanin. A recent study examined the use of diode lasers in mucosal surgery.
Its wavelength
The emission wavelength of a diode laser is determined by the material used for its construction. Different semiconductors have different band-gap energies, defining the spectral range of the laser’s emission. Other semiconductor alloys can be tuned to produce emission wavelengths that cover a broad range of wavelengths, from red to near-infrared and infrared to blue-ultraviolet.
A spectral profile that is Gaussian in shape is obtained by selecting the wavelength spectral width dl that is half the full wavelength modulation range Dl. This selection satisfies equation (4). However, it is impossible to match a Gaussian wavelength spectrum exactly due to the limitations of the current laser driver. A Gaussian function is a curve that extends infinity, but current diode laser modulation has a finite tuning range. However, a reasonable approximation can be generated.
Its optical modes
A Diode laser’s wavelength depends on the semiconductor’s band-gap and its optical modes’ wavelengths. Usually, light whose energy is above the band-gap is maximized. However, additional side modes can also lase depending on the current and temperature fluctuations. In addition, some Lasers operate at a single wavelength and may change their wavelength as time goes by.
The single-transverse mode of a Diode Laser is the most basic laser configuration. The beam appears to be an ideal point source, but it is anamorphic, as its divergence in two directions is different. As a result, many Single-spatial Mode lasers are slightly astigmatic. This amount can range from a few nanometers to several tens of microns, but it can be corrected with simple optics.
